Servomotor Rotates In The Wrong Direction; Maintenance Schedule - Grundfos Vaccuperm VGA-117 Montage- Und Betriebsanleitung

7.4 Servomotor does not run
Cause
Servomotor is switched to
manual operation.

7.5 Servomotor rotates in the wrong direction

Cause
Servomotor is adjusted
incorrectly.
Controller is adjusted
incorrectly.
7.6 In versions with differential-pressure regulator the
dosing capacity varies despite constant operating
conditions
Cause
The spring in the differential-
pressure regulator is soiled.
The spring in the differential-
pressure regulator is damaged.
The diaphragm in the
differential-pressure regulator is
soiled.
The diaphragm in the
differential-pressure regulator is
damaged.
7.7 In versions without differential-pressure regulator
the dosing capacity varies despite constant
operating conditions
Cause
At maximum capacity, the
injector vacuum is below 5
mH2O.
The injector used is not
suitable.
Motive water pressure is too
low.
Backpressure is too high.
The dirt trap before the injector
is soiled.
Remedy
• Switch servomotor to
automatic operation. See the
supplier manual of the
servomotor.
Remedy
• Adjust the servomotor. See
the supplier manual of the
servomotor.
Remedy
• Clean the spring in the
differential-pressure regulator.
• Replace the spring in the
differential-pressure regulator.
• Clean the differential-pressure
regulator.
• Replace the diaphragm in the
differential-pressure regulator.
Remedy
• Make sure that the injector
vacuum is at least 5 mH2O.
• Make sure that a suitable
injector type is used.
• Check if the injector functions
properly. Observe the manual
of the injector.
• Make sure that the motive
water pressure is sufficient.
• Make sure that the
backpressure is suitable. See
specification.
• Check the dirt trap before the
injector. Clean it, if necessary.
8. Maintenance
WARNING
Toxic material
Death or serious personal injury
‐
Cleaning and maintenance must be carried out by au-
thorised and trained experts.
‐
Observe the material safety data sheets (SDS) of the
handled chemicals.
‐
Wear personal protective equipment when handling
chemicals.
‐
Shut down the whole system before any work at the
system components and lines.
‐
The system must be pressureless.
‐
Separate the whole system from the power supply be-
fore any work at the system components.
‐
Safety installations, which have been disabled during
maintenance, must be enabled again immediately af-
ter maintenance.
‐
Tightly close inlet flanges and outlet flanges to prevent
humidity from getting in.
‐
Check the tightness of the whole system before re-
commissioning.
Observe the manuals of the system and all other compo-
nents.

8.1 Maintenance schedule

• Check the tightness of the whole system monthly.
• Check the electrical grounding of the whole system according to
local requirements.
• Check the VGA-117 dosing regulator at least every 12 months,
before start-up and in case of malfunction.
Systems without differential-pressure regulator require no
maintenance.
8.2 Cleaning the measuring glass of the flowmeter
A
Dismantling the measuring glass of the flowmeter
Required tools and accessories:
• Hot water
• Soft brush
1. Unscrew the lower support (A).
2. Pull out the measuring glass.
3. Take off the plugs of the measuring glass and take out the ball.
4. Clean all parts with hot water, use a brush if necessary.
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